| The goal of this research was to understand how plant diversity affects methane production and oxidation in wetlands. We sampled soils from two natural and two created freshwater wetlands in central Ohio and measured methane production and oxidation potentials in the laboratory. Soil sampling plots were selected to represent the range of plant diversity in each wetland. In the two natural wetlands, maximum methane production potentials were 1.5 and 7.9 ng CH 4 g-1 h-1, and oxidation potentials were 41.3 and 25.8 ng CH4 g-1 h-1. In the two created wetlands, maximum production potentials were 0.3 and 0.7 ng CH4 g-1 h-1, while oxidation potentials were 8.1 and 4.3 ng CH4 g-1 h-1. Natural wetlands had greater methane oxidation (P < 0.0001) than created wetlands and these rates increased with soil moisture ( P = 0.05, BF; 0.01, CA) and organic matter (P = 0.02, BF; 0.02, CA). Natural wetlands had greater soil moisture than created wetlands (P < 0:0001). There was no relationship between plant diversity and methane production and oxidation potentials. However, there were important differences in soil properties between natural and created wetlands. Therefore, the creation of mitigation wetlands must still account for soil properties and processes mediated by the soil microbial community in order to attain functional equivalence, which may be more difficult to restore on shorter time-scales than plant diversity. This is a particular concern because the amount of time needed to restore wetland function is unknown, yet short-term monitoring is common practice while long-term monitoring is rare and not obligatory. |
